The invention relates to the field of recombination lasers.
Recombination lasers have been produced by electronic discharge pumping as well as by laser-produced plasma pumping. Evidence of this is found in the following prior art references: (1) "Comparison of Radiation from Laser-Produced and DC-Heated Plasmas in Xenon", by W. T. Silfvast and O. R. Wood, II, Applied Physics Letters, Vol. 25, No. 5, September 1974, pp. 274-277, (2) "Recombination Lasers in Expanding CO.sub.2 Laser-Produced Plasmas of Argon, Krypton and Xenon", by W. T. Silfvast, L. H. Szeto and O. R. Wood, II, Applied Physics Letters, Vol. 31, No. 5, September 1977, pp. 334-337, and (3) "Recombination Lasers Utilizing Vapors of Chemical Elements I. Principles of Achieving Stimulated Emission Under Recombination Conditions", by V. V. Zhukov, E. L. Latush, V. S. Mikhalevskii and M. F. Sem, Soviet Journal of Quantum Electronics, Vol. 7, No. 6, June 1977, pp. 704-708.
References 2 and 3, as well as the following prior art references: (4) "Population Inversion with Respect to the Ground Level of an Ion or Atom by the Rapid Cooling of a Plasma", by J. M. Green and W. T. Silfvast, Applied Physics Letters, Vol. 28, No. 5, March 1976, pp. 253-255, and (5) "Recombination Laser from Cooled Hydrogen Plasma (Plasma Dynamic Laser)", by A. W. Ali and W. W. Jones, Physics Letters, Vol. 55A, No. 8, February 1976, pp. 462-464, indicate that the recombination rate of electrons and ions in the amplifying medium of a recombination laser is enhanced by cooling the electrons via collisions with a surrounding gas. This prediction has led investigators to attempt to increase the small-signal gain obtained from recombination lasers by combining inert gases at high pressures with a gaseous amplifying medium. The results obtained, as indicated in the above-cited prior art references, follow the expected trend.